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TREASURY DEPARTMENT 
Dlic Health and Marine-Hospital Service of the United States 



REPRINT FROM PUBLIC HEALTH REPORTS.— No. 78 



REPORT OF THE COMMISSION ON MILK 

STANDARDS APPOINTED BY THE 

NEW YORK MILK COMMITTEE 



(SECOND EDITION) 




WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1912 



Digitized by the Internet Archive 
in 2011 with funding from 
The Ubrary of Congress 



http://www.archive.org/details/reportofcommissi03comm 



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^REPORT OF THE COMMISSION ON MILK STANDARDS AP- 
POINTED BY THE NEW YORK MILK COMMITTEE. 1 

INTRODUCTION. 

PERSONNEL. 

1 he New York Milk Committee, which is a voluntary organization \ 
working in the interests of improving the milk supply of New York 
City, in March, 1911, decided to appoint a commission on milk stand- 
ards. The men who have served on the commission are as follows: 

Dr. W. A. Evans, professor preventive medicine, Northwestern University; health 
editor, Chicago Tribune, Chicago, 111., chairman. 

Dr. B. L. Arms, director of bacteriological laboratory, department of health, Boston, 
Mass. 

Dr. John F. Anderson, director of hygienic laboratory, United States Public Health 
and Marine-Hospital Service, Washington, D. C. 

Prof. H. W. Conn, director of bacteriological laboratory, Connecticut State Board of 
Health, department of biology, Wesleyan University, Middletown, Conn. 

Dr. E. C. Levy, health officer, Richmond, A r a. 

Dr. A. D. Melvin, Chief of Bureau of Animal Industry, United States Department 
of Agriculture, Washington, D. C. 

Dr. William H. Park, director of laboratories, department of health of New York 
City, foot of East Sixteenth Street, New York City. 

Mr. Raymond A. Pearson, commissioner of agriculture, Albany, N. Y. 

Dr. M. P. Ravenel, director of hygienic laboratory, University of Wisconsin, Madi- 
son, Wis. 

Prof. M. J. Rosenau, department of hygiene and preventive medicine, Harvard 
Medical School, Boston, Mass. 

Prof. Henry C. Sherman, department of chemistry, Columbia University, New 
York City. 

Dr. A. H. Stewart, antitoxin laboratories, department of health and charities, Phil- 
adelphia, Pa. 

Dr. William Royal Stokes, bacteriologist to State and city health departments, 
Baltimore, Md. 

Prof. William A. Stocking, department of dairy industry, Cornell University, 
Ithaca, N. Y. 

Mr. Chester H. Wells, health officer, Montclair, N. J. 

Dr. L. L. Van Slyke, department of chemistry, New York Agricultural Experiment 
Station, Geneva, N. Y. 

Dr. Charles E. North, consulting sanitarian, member New York Milk Committee, 
New York City, secretary. 

ORIGIN AND ORGANIZATION. 

The appointment of this commission was the direct result of the 
observation of the New York Milk Committee that there was great 
incompleteness and lack of uniformity in the milk standards, milk 
ordinances, and rules and regulations of public-health authorities 
throughout the country for the control of public-milk supplies. 

i Reprint from the Public Health Reports, Vol. XX VII, No. 19, May 10, 1912. 

(3) 



There was a need that health officers be furnished conclusions drawn 
from large experience and mature judgment and that ordinances should 
be as free from erroneous positions and as uniform as possible. 

A special committee of the New York Milk Committee was 
appointed to consider names of more than 200 men of prominence 
in medicine, sanitation, public health, and laboratory work, particu- 
lary those recognized as authorities on the milk question. Since 
regulations are based on standards and standards are based chiefly 
on laboratory analyses, the subcommittee selected 20 names of 
men distinguished for their knowledge of the bacteriological and 
chemical examination of milk and for the enforcement of standards 
based on such laboratory examinations. Two of those chosen 
declined to serve and another resigned after the first meeting, so 
that there were 17 members who have taken an active part in the 
work of the commission. 

PURPOSES. 

While this commission was created by and its expenses were borne 
by the New York Milk Committee, it has not been the intention of 
that committee that the commission should have the New York 
City milk problem solely in mind. It was desired that the commis- 
sion should make recommendations that might be adopted by any 
city or town in the country. 

MEETINGS. 

The first meeting of the commission was held in the New York 
Academy of Medicine on May 22, 1911. The chief work of that 
meeting consisted in a general discussion of the scope of the com- 
mission's purpose and the appointment of a number of standing 
committees to which the several divisions of the work were assigned. 
The subjects included bacteriological standards, chemical stand- 
ards, grades and classes of milk, standard ordinances, law x s, and 
licenses, and new questions. 

The second meeting of the commission was held at the New York 
Academy of Medicine on October 5 and 6, 1911, at which time the 
reports of the standing committees were received and modified, 
and the major part of them tentatively adopted. Special com- 
mittees were appointed at this time to consider certain specific 
matters which were presented and final action on all matters was 
deferred until the third and final meeting. 

The third and last meeting of the commission w r as held in Homer, 
N. Y., on January 25, and at the New York Academy of Medicine, 
January 26 and 27, 1912. The commission visited Homer in order 
that the members might inspect the central station and the dairy 
farms of the New York Dairy Demonstration Co. as a means of 
helping them to form a correct judgment of the relative value to 
be given to methods and equipment in the rules and regulations that 
they might recommend. 

The commission voted to divide its report into a preamble of 
explanation and a report containing its resolutions regarding milk 
standards and rules and regulations. 



\ 



5 
PREAMBLE. 

NEED OF MILK CONTROL. 

Proper milk standards, while they are essential to efficient milk 
control by public health authorities and have as their object the 
protection of the milk consumer, are also necessary for the ultimate 
well-being of the milk industry itself. Public confidence is an asset 
of the highest value in the milk business. The milk producer is 
interested in proper standards for milk, since these contribute to the 
control of bovine tuberculosis and other cattle diseases and dis- 
tinguish between the good producer and the bad producer. The milk 
dealer is immediately classified by milk standards, either into a seller 
of first-class milk or a seller of second-class milk, and such distinc- 
tion gives to the seller of first-class milk the commercial rewards 
which he deserves, while it inflicts just penalties on the seller of second- 
class milk. For milk consumers, the setting of definite standards 
accompanied by proper labeling makes it possible to know the char- 
acter of the milk which is purchased and to distinguish good milk from 
bad milk. In the matter of public health administration, standards 
are absolutely necessary to furnish definitions around which the rules 
and regulations of city health departments can be drawn, and the 
milk supply efficiently controlled. 

PUBLIC HEALTH AUTHORITIES. 

While public health authorities must necessarily see that the 
source of supply and the chemical composition should correspond with 
established definitions of milk as a food, their most important duty 
is to prevent the transmission of disease through milk. This means 
the control of infantile diarrhea, typhoid fever, tuberculosis, diph- 
theria, scarlet fever, septic throat infections, and other infectious 
diseases in so far as they are carried by milk. 

SEPTIC SORE THROAT. 

Septic sore throat deserves special mention because of the fre- 
quency in recent years with which outbreaks of this disease have been 
traced to milk supplies. The suggestion has been made that the 
infection of the milk is due to udder infection of the cow and on the 
other hand it has been suggested that it is due to contact with infected 
persons. The uncertainty can not be dispelled until cases of septic 
sore throat are regularly reported and tabulated by public health 
authorities. The commission therefore recommends that public 
health authorities make septic sore throat a reportable disease. 

ECONOMIC PROBLEM. 

The commission recognizes the magnitude of the milk industry, 
and that the improvement of milk supplies is primarily an economic 
problem. The success achieved by the experiment in milk produc- 
tion, which has been carried out on a very large scale by the New York 
Dairy Demonstration Co., is an illustration of the fact that an extra 
price or premium paid to the producer for cleanliness and care will 



bring results far more quickly and certainly than instructions or offi- 
cial inspection. But while the basic problem is economic, and must 
eventually be solved by commerce, public health authorities must 
show the way and must establish standards and regulations in the 
interest of consumers, the value of which even the consumers them- 
selves often fail to appreciate. 

LEGAL REQUIREMENTS. 

A prime requisite of effectiveness is that local milk laws shall not 
exceed sanitary limitations. The commission has not entered into a 
discussion of fundamental State laws, but it recommends that State 
laws be amended wherever necessary in order that every municipality 
may have the legal right to adopt whatever ordinances it sees fit for 
the improvement of the milk supply. The commission advocates 
that local health laws be carefully drawn with regard to their legality 
under the general laws of the localities to which they apply, since a 
decision against a milk law in one locality is liable to be used as a prec- 
edent against milk laws elsewhere. 

STANDARD RULES AND REGULATIONS. 

The commission has drawn up a set of standard rules and regula- 
tions for the control of milk. These are the result of a study of the 
printed rules and regulations of the cities of the United States and of 
foreign countries and represent an immense amount of work on the 
part of the special committee of the commission to which the task was 
assigned. Some communities are in a position to adopt all of these 
rules and regulations at the present time, while other communities 
will be obliged to adopt a few rules at a time as public sentiment and 
local conditions warrant. It is realized that some of the rules may 
have to be modified to meet local conditions. It seems wise to the 
commission to divide the regulations into two parts: First, require- 
ments, under which head are set down those provisions which are so 
fundamentally necessary that no community is justified in compromis- 
ing on them; second, recommendations, under which head are set 
down provisions which are necessary for a good milk supply, but on 
which there can be a certain amount of latitude for compromise b}* 
those communities in which public sentiment is not ready to support 
more than a moderate degree of protection of human life. 

ADMINISTRATIVE EQUIPMENT. 

Another prime requisite is that the administrative departments 
shall be adequately equipped with men, money, and laboratory 
facilities. In smaller communities cooperation between local boards 
of health to the extent of exchanging reports would eliminate much 
duplication. Where a community can not maintain a laboratory it 
can enter into laboratory arrangements with other communities, and 
several can combine in the use of a common laboratory. Much of the 
expense of tuberculin testing can be borne by the National and State 
Governments. The commission is of the opinion that results can not 
be expected from laws where there is not sufficient appropriation and 



no machinery for their enforcement. On this subject the commission 
passed a resolution as follows: 

Whereas the appropriations generally made for the purposes of carrying on laboratory 
analyses of milk are now in most cases entirely inadequate: Therefore be it 

Resolved, That this commission recommends for the consideration of the authorities 
concerned an appropriation of funds commensurate with the importance of laboratory 
methods, which are of paramount importance in the hygienic control of the milk supply. 

CLASSIFICATION OF MILKS. 

There is no escape from the conclusion that milk must be graded 
and sold on grade, just as wheat, corn, cotton, beef, and other products 
are graded. The milk merchant must judge of the food value and 
also of the sanitary character of the commodity in which he deals. 
The high-grade product must get a better price than at present. 
The low-grade product must bring less. In separating milk into 
grades and classes the commission has endeavored to make its classi- 
fication as simple as possible and at the same time to distinguish 
between milks which are essentially different in sanitary character. 

In general two great classes of milk are recognized, namely, raw 
milk and pasteurized milk. Under these general classes there are 
different grades, as indicated in the report of the committee on 
classification. 

PASTEURIZATION. 

While the process of pasteurization is a matter which has attracted 
a great deal of attention in recent years, the commission has not 
entered into any discussion of its merits or demerits, but has given it 
recognition in its classification as a process necessary for the treatment 
of milk which is not otherwise protected against infection. 

The commission thinks that pasteurization is necessary for all milk 
at all times excepting certified milk or its equivalent. The majority 
of the commissioners voted in favor of the pasteurization of all milk, 
including certified. Since this was not unanimous, the commission 
recommends that the pasteurization of certified milk be optional. 

PASTEURIZING TEMPERATURES. 

The destruction of the chemical constituents of milk by heat occurs 
at higher temperatures than those necessary for the destruction of the 
bacteria of infectious diseases transmissible by milk. (See chart in 
appendix.) 

The commission passed a resolution regarding the temperature of 
pasteurization as follows: 

That pasteurization of milk should be between the limits of 140° F. and 155° F. 
At 140° F. the minimum exposure should be 20 minutes. For every degree above 
140° F. the time may be reduced by 1 minute. In no case should the exposure be for 
less than 5 minutes. 

In order to allow a margin of safety under commercial conditions, 
the commission recommends that the minimum temperature during 
the period of holding should be made 145° F. and the holding time 20 
minutes. Pasteurization in bulk when properly carried out has 
proven satisfactory, but pasteurization in the final container is 
preferable. 



LABELING AND DATING OF MILK. 

The commission voted that all milk should be labeled and marked 
with the grade in which it is to be sold. In dating milk uniform 
methods should be adopted for all grades of both raw milk and pas- 
teurized milk, both using the day of the week or both using the day of 
the month. All milk should be dated uniformly with the date of 
delivery to the consumer. Kaw milk should not be dated with the 
date of production while pasteurized milk is dated with the date of 
pasteurization, since this places certified milk at a disadvantage by 
making it possible for pasteurized milk of a lower grade to carry a 
later date. The stamping on the label of the day of the week is suffi- 
cient for dating. 

BACTERIA. 

The subject of bacteria in milk received more attention than any 
other matter brought before the commission. The commission recog- 
nizes that bacteria in milk in the majority of instances indicate dirt, 
or lack of refrigeration, or age, while in the minority of instances the 
bacteria of disease may be present. The routine laboratory methods 
for examining milk have as their purpose only the control over dirt, 
refrigeration, and age, and it is a rare thing for a laboratory to under- 
take the examination of milk for the bacteria of disease. Milk with a 
high bacterial count is not necessarily harmful, but when used as a 
food, particularly for children, is a hazard too great to be warranted. 
Milk with a high bacteria count, therefore, should be condemned. 
Milks with small numbers of bacteria are presumed to be wholesome, 
unless there is reasonable ground for suspecting that they have been a 
exposed to contagion. / 



/ 



BACTERIAL STANDARDS. 



The commission recognizes the difficulty in interpreting bacterial 
counts. At times misleading conclusions have been drawn from such 
counts. In establishing the bacterial standards for a city it is always 
necessary to take into consideration the necessary age of the milk and 
in lesser measure the distance hauled and methods employed in its 
hauling. It will always be possible for a community which consumes 
milk produced on its own premises, or within 12 hours of its produc- 
tion, to insist upon and maintain a lower bacterial standard than can 
one where the milk is hauled many miles into town in a wagon, to be 
consumed within 24 hours after it is produced. In like manner this 
second type of city can always maintain a lower bacterial standard 
than a city where the general milk supply is hauled by railroad long 
distances and is several days old when consumed. In drawing con- 
clusions as to the relative efficacy of milk control in cities comparisons 
must be made between cities of the same class. 

The commission deems it of the utmost importance that some 
standard method should be adopted for estimating and comparing the 
bacterial character of milks, since by this means only is it possible to 
grade and classify milks and to enforce bacterial standards. There is 
much diversity of opinion as to the best method of valuing bacterial 
counts. The average of a series gives results which are misleading 
about as frequently as otherwise. In the average a single high figure 



9 

may unduly overbalance a large number of exceedingly low counts. 
There are objections to the use of the "median" or middle number 
when the counts are arranged in order of size, for the reason that the 
middle figure does not distinguish between two groups in one of which 
there may be some very high counts above the median and in the 
other of which there are none. The method of dividing results into 
groups as recommended by the American Public Health Association, 
while a step in the right direction, is cumbersome and does not clearly 
indicate whether a milk conforms or not to a given bacterial standard. 
In this dilemma the commission has adopted some special methods of 
stating the results of bacterial counts. It recommends the use of a 
single figure, called "the bacterial content," as the means of deter- 
mining whether a milk conforms to given bacterial standards and for 
determining the class to which milk belongs. These methods are 
described in detail in the appendix. 

The bacterial standards given in the report are the work of a special 
committee of bacteriologists who considered all of the bacterial stand- 
ards now in use. It is believed that the standards suggested are fair 
and wise and give full consideration to the state of the industr} r and of 
public-health control. The commission believes that the adoption 
and enforcement of these bacterial standards will be more effective 
than any other one thing in improving the sanitary character of public 
milk supplies. The enforcement of these standards can only be car- 
ried out by the regular and frequent laboratory examinations of milks 
for the numbers of bacteria they may contain. / 

CHEMICAL STAND AEDS. 

The chemical standards suggested are the work of a special com- 
mittee, composed of chemists, which has carefully considered the 
natural composition of milk and the Federal and State standards 
already established. The standard of 3.25 per cent fat and 8.5 per 
cent solids, not fat, here proposed is in accordance with the recommen- 
dations of the Association of Official Agricultural Chemists and has 
been adopted by the United States Department of Agriculture and by 
a larger number of States than has any other standard. The simplifi- 
cation of the Babcock test makes the determination of fats and solids 
not fat an easy procedure quickly applied. Such chemical examina- 
tions of milk can be readily adopted and executed b} 1 " any health board 
laboratory at a very moderate expense. It is believed that such chem- 
ical standards as are suggested will inflict no real hardship on the milk 
producers of this country and that the provision regarding substand- / 
ard milks is a liberal one. 

MICEOSCOFIC EXAMINATION OF MILK. 

Some of the special methods of milk examination recently devised 
having as their object the determination of the numbers of bacteria 
directly by the use of the microscope, the presence of pus by sedimen- 
tation and microscopical examination, and the presence of gross dirt 
by filtration were deemed of such importance that the subjects were 
assigned to a special committee. The committee has made extensive 
studies of these methods, which are the subject of a special report. 
(See appendix.) 

49439—12 2 



10 

PUBLICITY. 

The commission fully considered the matter of the publication of 
laboratory examinations of milk by city and town health authorities. 
When proper standards and regulations are established and adequate 
facilities furnished for laboratory work, it is believed that the labora- 
tory tests will give an index of the character of the milk delivered to 
the public by milk sellers which is entirely fair and impartial. There 
can oe no objection to publicity under such circumstances. It is an 
advantage to the seller of high-grade milk. It is an advantage to the 
consumer who desires to select a high-grade milk. It has much edu- 
cational value both to producer and consumer. Therefore the com- 
mission recommends "that the reports of laboratory analyses of milk 
made by departments of health be regularly published." 

KEPORT. 

CLASSIFICATION OF MILK. 

Milk should be graded and classified. The classification should be 
the same for both large and small cities and towns. Milk should be 
graded into four classes, as follows : 

Class A. — Certified milk or its equivalent. 

Class B. — Inspected milk. 

Class C. — Pasteurized milk. 

Class D. — Milk not suitable for drinking purposes. 

Class A. Certified milk or its equivalent. — The use of the term cer- 
tified should be limited to milk produced in conformity with the 
requirements of the American Association of Certified Milk Com- 
missions. 

Milk of an equivalent character should conform to the following 
requirements: It should be produced at dairies subjected to periodic 
inspection and the products of which are subject to frequent analyses. 
The cows producing such milk must be properly fed and watered, 
free from tuberculosis as shown by the tuberculin test and phyiscal 
examination by a qualified veterinarian, and from all other com- 
municable diseases, and from diseases and conditions whatsoever 
likely to deteriorate the milk. They must be housed in clean, prop- 
erly ventilated stables of sanitary construction, and must be kept 
clean. All persons who come in contact with the milk must exercise 
scrupulous cleanliness and must not harbor the germs of typhoid 
fever, tuberculosis, diphtheria, dysentery, scarlet fever, and septic 
throat infections, or other infections liable to be conveyed by the milk. 
Milk must be drawn under all precautions necessary to avoid infec- 
tion, and be immediately strained and cooled, placed in sterilized 
bottles, and kept at a temperature not exceeding 50° F. until delivered 
to the consumer. Pure water, as determined by inspection and 
chemical and bacteriological examination, is to be provided for use 
throughout the dairy farm and dairy. Milk of this class should con- 
tain less than 10,000 bacteria per cubic centimeter, and should not 
be more than 28 hours old when delivered. 

Class B. Inspected milk. — This class should consist of clean raw 
milk from healthy cows, as determined by the tuberculin test and 
physical examination by a qualified veterinarian, and from dairies 



11 

that score not less than 70 on the Government score card. The cows 
are to be fed, watered, housed, and niilked under good conditions, 
but not necessarily equal to the conditions prescribed for class A. 
All persons who come in contact with the milk must exercise scrupu- 
lous cleanliness and must not harbor the germs of typhoid fever, 
tuberculosis, diphtheria, or other infectious diseases liable to be con- 
veyed by milk. This milk is to be delivered in sterilized containers 
and is to be kept at a temperature not exceeding 50° F. until it reaches 
the consumer. It should contain less than 100.000 bacteria per cubic 
centimeters. Pasteurization of milk of this class is optional. If 
pasteurized it shall then be designated as •'pasteurized inspected 
milk.'' 

Class C. Pasteurized mflfk. — Milk from dairies not able to comply 
with the requirements specified for classes A and B should be pas- 
teurized under official supervision before being sold, and should be 
sold under the designation ' "pasteurized milk." Milk for pasteuriza- 
tion should be kept at a temperature not exceeding 50° F. at all times 
while in transit from the dairy farm to the pasteurizing plant. After 
pasteurization it should be placed in sterilized containers (if not pas- 
teurized in such containers) and should be cooled at once to 50° F. 
and kept below that temperature until delivered to the consumer. 
Xo cows in any way unfit for the production of milk for use by man, 
as determined by physical examination, shall be permitted to remain 
in any dairy producing milk of class C. Such milk before pasteuriza- 
tion should contain less than 1.000.000 bacteria per cubic centimeter, 
and after pasteurization less than 50,000, and it should not contain 
colon bacilli in 1 cubic centimeter as determined by cultural methods. 
Pasteurized milk should be delivered to the consumer within less than 
48 hours after pasteurization. The repasteurization of milk should 
be prohibited. 

Class D. Milk not suitable for drinking purposes. — Milk containing 
over 1,000,000 bacteria per cubic centimeter, or from farms scoring 
less than 40 per cent, may be allowed to be sold for cooking and in- 
dustrial purposes only after having been pasteurized or heated to a 
higher temperature. Such milk should be delivered in a distinctive 
container, and should not be allowed to be sold for drinking purposes. 

CLASSIFICATION OF CREAM. 

Cream should be classified into the same grades as milk, in accord- 
ance with the requirements for the grades of milk, with special bac- 
terial standards which should not exceed 30.000 per cubic centimeter 
in the case of grade A. and 300,000 per cubic centimeter in the case 
of grade B. Bacterial limits for grades C and D can not at the present 
time be specified. 

BACTERIOLOGICAL STANDARDS. 

Class A milk shall contain less than 10,000 bacteria per cubic centi- 
meter. 

Class B milk shall contain less than 100,000 bacteria per cubic cen- 
timeter. 

Class C milk shall contain less than 1,000,000 bacteria per cubic 
centimeter before pasteurization and less than 50,000 bacteria per 



12 

cubic centimeter after pasteurization, and should not contain colon 
bacilli in 1 cubic centimeter as determined by cultural methods. 

On the subject of laboratory examinations of milk for bacteria, 
the commission passed the following resolutions : 

1. That the interests of public health demand that the control of milk supplies shall 
include regular laboratory examinations of milk by bacteriological methods. 

2. That among present available routine laboratory methods for determining the 
sanitary quality of milk the bacteria count occupies first place. 

3. That bacteriological standards should be a factor in classifying or grading milks 
»f different degrees of excellence. 

4. That bacteriological examinations of milk are of importance at every stage of 
production and distribution, but that in the establishment of grades and classes of 
jaw milk such grades and classes should be based on the bacterial content of milk as 
offered for sale. 

5. That there should be bacteriological standards for milk before it is pasteurized 
and for milk after it is pasteurized. 

6. That the bacteria count of milk indicates its quality and history as it is modified 
by unusual contamination, improper handling, dirt, improper refrigeration, or age. 
The high count indicates the necessity of investigation and inspection in order that 
remedies may be applied. 

7. That there be adopted as standards for making the bacteria count the standard 
methods of the American Public Health Association, laboratory section, recommending, 
however, the following amendments: 

A. The methods of taking samples for laboratory tests for bacterial counts 
should be the same and uniform for all grades and classes of milk. 

B. That 1£ per cent agar be used instead of 1 per cent agar. 

C. That incubation of plate cultures be made at 37° C. for 48 hours, and that 
there be no option. 

D. That the minimum number of bacteria tests of milk necessary to warrant 
the publication of results be made four consecutive bacteria counts of separate 
samples within a period of not more than four weeks. 

CHEMICAL STANDARDS. 

Cow's milk. — Standard milk should contain not less than 8.5 per 
cent of milk solids not fat and not less than 3.25 per cent of milk fat. 

Skim milk. — Standard skim milk should contain not less than 8.75 
per cent of milk solids. 

Cream. — Standard cream contains not less than 18 per cent of milk 
fat and is free from all constituents foreign to normal milk. The 
percentage of milk fat in cream over or under that standard should be 
stated on the label. 

Buttermilk. — Buttermilk is the product that remains when fat is 
removed from milk or cream, sweet or sour, in the process of churn- 
ing. Standard buttermilk contains not less than 8.5 per cent of milk 
solids. When milk is skimmed, soured, or treated so as to resemble 
buttermilk, it should be known by some distinctive name. 

HOMOGENIZED MILK OR CREAM. 

The commission is of the opinion that in the compounding of milk 
mo fats other than milk fats from the milk in process should be used 
and that no substance foreign to milk should be added to it. The 
commission is opposed to the use of condensed milk or other mate- 
rials for the thickening of cream unless the facts are clearly set forth 
on the label of the retail package. Regarding the process of homo- 
genizing the commission resolved as follows: 

That homogenized milk or cream should be so marked, stating the percentage of fat 
'5hat it contains. 



ADJUSTED MILKS. 

On the question of milks and creams in which the ratio of the fats 
to the solids not fat has been changed by the addition to or subtrac- 
tion of cream or milk fat the commission has hesitated to take a 
position. On the one hand they are in favor of every procedure 
which will increase the market for good milk and make the most 
profitable use of every portion of it. On the other, they recognize 
the sensitiveness of milk, the ease with which it is contaminated, and 
the difficulty of controlling, standardizing, sldmming, homogenizing, 
souring, etc., so that contaminations do not occur and inferior mate- 
rials are not used. On this subject the commission passed a resolu- 
tion presented by a special committee as follows: 

Milk in which the ratio of the fats to the solids not fat has been changed by the 
addition to or subtraction of cream should be labeled "adjusted milk;" the label 
should show the minimum guaranteed percentage of fat and should comply with the 
same sanitary or chemical requirements as for milk not so standardized or modified, 

REGULATION OF MARKET MILK ON BASIS OF GUARANTEED PERCENT- 
AGE COMPOSITION. 

1. Sellers of milk should be permitted choice of one of two systems 
in handling market milk. Milk can be sold, first, under the regular 
standard, or, second, under a guaranteed statement of composition, 

2. Any normal milk may be sold if its per cent of fat is stated. la 
case the per cent of fat is not stated, the sale will be regarded as a 
violation unless the milk contains at least 3.25 per cent of milk fat. 

3. As a further protection to consumers, it is desirable that when 
the guaranty system is used there be also a minimum guaranty of 
milk solids not fat of not less than 8.5 per cent. 

4. Dealers electing to sell milk under the guaranty system should 
be required to state conspicuously the guaranty on all containers in 
which such milk is handled by the dealer or delivered to the con- 
sumer. 

5. The sale of milk on a guaranty system should be by special per- 
mission obtained from some proper local authority. 

STANDARD RULES FOR THE PRODUCTION, HANDLING, AND DISTRI- 
BUTION OF MILK. 

As a basis for the promulgation of rules and recommendations gov- 
erning the production, handling, and distribution of milk, it is recog- 
nized that we have to deal with two kinds of milk, raw and pasteur- 
ized, although there may be several grades of each of these two kinds. 
In order for any grade to be safe, it is recommended that the regula- 
tions herein set forth under the heading "Requirements" should be 
enforced. The regulations herein set forth under the heading "Rec- 
ommendations" should be adopted wherever practicable as a means 
of improving the milk supply above the actual point of safety. (The 
term "milk" shall be construed to include the fluid derivatives of 
milk wherever such construction of the term is applicable.) 



14 

LICENSES. 

REQUIREMENTS. 

No person shall engage in the sale, handling, or distribution of milk 

in until he has obtained a license therefor from the health 

authorities. This license shall be renewed on or before the 1st day of 

of each year and may be suspended or revoked at any time 

for cause. 

RECOMMENDATIONS. 

The application for the license shall include the following statements: 

(1) Kind of milk to be handled or sold. 

(2) Names of producers with their addresses and permit numbers. 

(3) Names of middlemen with their addresses. 

(4) Names and addresses of all stores, hotels, factories, and restaurants at which milk 
is delivered. 

(5) A statement of the approximate number of quarts of milk, cream, buttermilk, 
and skim milk sold per day. 

(6) Source of water supply at farms and bottling plants. 

(7) Permission to inspect all local and out-of-town premises on which milk is pro- 
duced and handled. 

(8) Agreement to abide by all the provisions of State and local regulations. 

PERMITS. 

REQUIREMENTS. 

No person shall engage in the production of milk for sale in , 

nor shall any person engage in the handling of milk for shipment 

into — until he has obtained a permit therefor from the health 

authorities. This permit shall be renewed on or before the 1st 

day of of each year and may be suspended or revoked at any 

time for cause. 

Raw Mills. 

COW STABLES. 

REQUIREMENTS. 

1. They shall be used for no other purpose than for the keeping of 
cows, and shall be light, well ventilated, and clean. 

2. They shall be ceiled overhead if there is a loft above. 

3. The floors shall be tight and sound. 

4. The gutters shall be water-tight. 

RECOMMENDATIONS. 

1. The window area shall be at least 2 square feet per 500 cubic feet of air space 
and shall be uniformly distributed, if possible. If uniform distribution is impossible, 
sufficient additional window area must be provided so that all portions of the barn 
shall be adequately lighted. 

2. The amount of air space shall be at least 500 cubic feet per coy , and adequate 
ventilation besides windows shall be provided. 

3. The walls and ceilings shall be whitewashed at least once every six months, unless 
the construction renders it unnecessary, and shall be kept free from cobwebs and dirt. 

4. All manure shall be removed at least twice daily and disposed of so as not to be 
a source of danger to the milk either as furnishing a breeding place for flies or otherwise. 

5. Horse manure shall not be used in the cow stable for any purpose. 



15 

MILK ROOM. 

REQUIREMENTS. 

Every milk farm shall be provided with a milk room that is clean, 
light, and well screened. It shall be used for no other purpose than 
for the cooling, bottling, and storage of milk and the operations inci- 
dent thereto. 

RECOMMENDATIONS. 

1. It shall have no direct connection with any stable or dwelling. 

2. The floors shall be of cement or other impervious material, properly graded and 
drained. 

3. It shall be provided with a sterilizer unless the milk is sent to a bottling plant, 
in which case the cans shall be sterilized at the plant. 

4. Cooling and storage tanks shall be drained and cleaned at least twice each week. 

5. All drains shall discharge at least 100 feet from any milk house or cow stable. 

COWS. 

REQUIREMENTS. 

1. A physical examination of all cows shall be made at least once 
every six months by a veterinarian approved by the health authorities. 

2. Every diseased cow shall be removed from the herd at once and 
no milk from such cows shall be offered for sale. 

3. The tuberculin test shall be applied at least once a year by a 
veterinarian approved by the health authorities. 

4. All cows which react shall be removed from the herd at once, 
and no milk from such cows shall be sold as raw milk. 

5. No new cows shall be added to a herd until they have passed 
a physical examination and the tuberculin test. 

6. Cows, especially the udders, shall be clean at the time of milking. 

7. No milk that is obtained from a cow within 15 days before or 5 
days after parturition, nor any milk that has an unnatural odor or 
appearance, shall be sold. 

8. No unwholesome food shall be used. 

RECOMMENDATIONS. 

1. Every producer shall allow a veterinarian employed by the health authorities to 
examine his herd at any time under the penalty of having his supply excluded. 

2. Certificates showing the results of all examinations shall be filed with the health 
authorities within 10 days of such examinations. 

3. The tuberculin tests shall be applied at least once every six months by a veteri- 
narian approved by the health authorities, unless on the last previous test no tubercu- 
losis was present in the herd or in the herds from which new cows were obtained, in 
which event the test may be postponed an additional six months. 

4. Charts showing the results of all tuberculin tests shall be filed with the health 
authorities within 10 days of the date of such test. 

5. The udders shall be washed and wiped before milking. 

EMPLOYEES. 

REQUIREMENTS. 

1. All employees connected in any way with the production and 
handling of milk shall be personally clean and shall wear clean outer 
garments. 

2. The health authorities shall be notified at once of any communi- 
cable disease in any person that is in any way connected with the 



16 

production or handling of milk, or of the exposure of such person to 
any communicable disease. 

3. Milking shall be done only with dry hands. 

RECOMMENDATIONS. 

1 . Clean suits shall be put on immediately before milking. 

2. The hands shall be washed immediately before milking each cow, in order to 
avoid conveyance of infection to the milk. 

UTENSILS. 

REQUIREMENTS. 

1. All utensils and apparatus with which milk comes in contact 
shall be thoroughly washed and sterilized, and no milk utensil or 
apparatus shall be used for any other purpose than that for which it 
was designed. 

2. The owner's name, license number, or other identification mark, 
the nature of winch shall be made known to the health authorities, 
shall appear in a conspicuous place on every milk container. 

3. No bottle or can shall be removed from a house in winch there 
is, or in which there has recently been, a case of communicable dis- 
ease until permission in writing has been granted by the health 
authorities. 

4. All metal containers and piping shall be in good condition at 
all times. All piping shall be sanitary milk piping, in couples short 
enough to be taken apart and cleaned with a brush. 

5. Small-top milking pails shall be used. 

RECOMMENDATIONS. 

1. All cans and bottles shall be cleaned as soon as possible after being emptied. 

2. Every conveyance used for the transportation or delivery of milk, public car- 
riers excepted, shall bear the owner's name, milk-license number, and business 
address in uncondensed gothic characters at least 2 inches in height. 

MILK. 

REQUIREMENTS. 

1. It shall not be strained in the cow stable, but shall be removed 
to the milk room as soon as it is drawn from the cow. 

2. It shall be cooled to 50° F. or below within two hours. after it 
is drawn from the cow and it shall be kept cold until it is delivered 
to the consumer. 

3. It shall not be adulterated by the addition to or the subtraction 
of any substance or compound, except for the production of the fluid 
derivatives allowed by law. 

4. It shall not be tested by taste at any bottling plant, milk house, 
or other place in any way that may render it liable to contamination. 

5. It shall be bottled only in a milk room or bottling plant for 
which a license or permit has been issued. 

6. It shall be delivered in bottles, or single service containers, 
with the exception that 20 quarts or more may be delivered in bulk 
in the following cases: 



17 

(a) To establishments in which milk is to be consumed or used on 
the premises. 

(b) To infant-feeding stations that are under competent medical 
supervision. 

7. It shall not be stored in or sold from a living room or from any 
other place winch might render it liable to contamination. 

RECOMMENDATIONS. 

1. It shall be.cooled to 50° F. or below Immediately after milking and shall be kept 
at or below that temperature until it is delivered to the consumer. 

2. It shall contain no visible foreign material. 

3. It shall be labeled with the date of production. 

RECEIVING STATIONS AXD BOTTLING PLANTS. 

REQUIREMENTS. 

1. They shall be clean, well screened, and lighted, and shall be used 
for no other purpose than the proper handling of milk and the opera- 
tions incident thereto, and shall be open to inspection by the health 
authorities at any time. 

2. They shall have smooth, impervious floors, properly graded and 
drained. 

3. They shall be equipped with hot and cold water and steam. 

4. Ample provision shall be made for steam sterilization of all 
utensils, and no empty milk containers shall be sent out until after 
such sterilization. 

5. All utensils, piping, and tanks shall be kept clean and shall be 
sterilized daily. 

RECOMMENDATIONS. 

1. Containers and utensils shall not be washed in the same room in which milk is 
handled. 

STORES. 

REQUIREMENTS. 

1. All stores in which milk is handled shall be provided with a suit- 
able room or compartment in which the milk shall be kept. Said 
compartment shall be clean and shall be so arranged that the milk 
will not be liable to contamination of any kind. 

2. Milk shall be kept at a temperature not exceeding 50° F. 

RECOMMENDATIONS. 

1. Milk to be consumed off the premises may be sold from stores only in the original 
unopened package. 

GENERAL REGULATIONS. 

REQUIREMENTS. 

1. The United States Bureau of Animal Industry score card shall 
be used, and no milk from a dairy that scores below 70 on such card 
shall be sold. 

2. Every place where milk is produced or handled and every con- 
veyance used for the transportation of milk shall be clean. 

49439—12 3 



18 

3. All water supplies shall be from uncontaminated sources and 
from sources not liable to become contaminated. 

4. The license or permit shall be kept posted in a conspicuous place 
in every establishment for the operation of which a milk license or 
permit is required. 

5. No milk license or permit shall at any time be used by any per- 
son other than the one to whom it was granted. 

6. No place for the operation of which a license or permit is granted 
shall be located within 100 feet of a privy or other possible source of 
contamination, nor shall it contain or open into a room which con- 
tains a water-closet. 

7. No skim milk or buttermilk shall be stored in or sold from cans 
or other containers unless such containers are of a distinctive color 
and permanently and conspicuously labeled "skim milk" or "butter- 
milk/' as the case may be. 

8. No container shall be used for any other purpose than that for 
which it is labeled. 

RECOMMENDATIONS. 

1. Ice used for cooling purposes shall be clean and uncontaminated. 

2. No person whose presence is not required shall be permitted to remain in any 
cow stable, milk house, or bottling room. 

SUBNORMAL MILK. 

REQUIREMENTS. 

1. Natural milk that contains less than 3.25 per cent, but more 
than 2.5 per cent milk fat, and that complies in all other respects with 
the requirements above set forth, may be sold, provided the percent- 
age of fat does not fall below a definite percentage that is stated in a 
conspicuous manner on the container; and further provided that 
such container is conspicuously marked "substandard milk." 

CREAM. 

REQUIREMENTS AND RECOMMENDATIONS. 

1. It shall be obtained from milk that is produced and handled in 
accordance with the provisions hereinbefore set forth for the produc- 
tion and handling ofrnilk. 

STANDARDS FOR MILK. 

REQUIREMENTS. 

1. It shall not contain more than 100,000 bacteria per cubic centi- 
meter. 

2. It shall contain r not less than 3.25 per cent milk fat. 

3. It shall containjnot less than 8.5 per cent solids not fat. 

RECOMMENDATIONS. 

l.The bacterial limit shall be lowered if possible. 



19 

STANDARDS FOR CREAM. 

REQUIREMENTS. 



1. It shall not contain more than 300,000 bacteria per cubic centi- 
meter. 

2. It shall contain not less than 18 per cent milk fat. 

RECOMMENDATIONS. 

Same as above for milk. 

STANDARDS FOR SKIM MILK. 

REQUIREMENTS. 

1 . It shall contain not less than 8.75 per cent milk solids. 

2. Control of sale of skim milk: Whether skim milk is sold in 
wagons or in stores, all containers holding skim milk should be painted 
some bright, distinctive color and prominently and legibly marked 
"skim milk." When skim milk is placed in the buyer's container, a 
label or tag bearing the words "skim milk" should be attached. 

Pasteurized Milk. 

Pasteurized milk is milk that is heated to a temperature of not less 
than 140° F. for not less than 20 minutes, or not over 155° F. for not 
less than 5 minutes, and for each degree of temperature over 140° F. 
the length of time may be 1 minute less than 20. Said milk shall be 
cooled immediately to 50° F. or below and kept at or below that 
temperature. 

COW STABLES. 

REQUIREMENTS. 

The same as for the production of raw milk. 

RECOMMENDATIONS. 

The same as for the production of raw milk. 

MILK ROOM. 

REQUIREMENTS. 

The same as for the production of raw milk. 

RECOMMENDATIONS. 

The same as for the production of raw milk. 

cows. 

REQUIREMENTS. 

The same as for the production of raw milk, with the exception of 
the sections relating to the tuberculin test. 

RECOMMENDATIONS. 

That no cows be added to a herd excepting those found to be free from tuberculosis 
by the tuberculin test. 



20 

EMPLOYEES. 

REQUIREMENTS. 

The same as for the production of raw milk. 

RECOMMENDATIONS. 

The same as for the production of raw milk. 

UTENSILS. 

REQUIREMENTS. 

The same as for the production of raw milk. 

RECOMMENDATIONS. 

The same as for the production of raw milk. 

MILK FOR PASTEURIZATION. 

REQUIREMENTS. 

1. The same as for the production of raw milk, with the exception 
of sections 1, 2, and 6b. 

2. It shall be cooled to 60° F. or below within two hours after it 
is drawn from the cow, and it shall be held at or below that tempera- 
ture until it is pasteurized. After pasteurization, it shall be held at a 
temperature not exceeding 50° F. until delivered to the consumer. 

3. Pasteurized milk shall be distinctly labeled as such, together 
with the temperature at which it is pasteurized, and the shortest 
length of exposure to that temperature and the date of pasteur- 
ization. 

RECOMMENDATIONS. 

1. No milk shall be repasteurized. 

2. The requirements governing the production and handling of milk for pasteuri- 
zation should be raised wherever practicable. 

PASTEURIZING PLANTS. 

REQUIREMENTS. 

The same as under "Keceiving stations and bottling plants" for 
raw milk. 

RECOMMENDATIONS. 

The same as under "Receiving stations and bottling plants" for raw milk. 

STORES. 

REQUIREMENTS. 

The same as for raw milk. 

RECOMMENDATIONS. 

The same as for raw milk. 



21 

GENERAL REGULATIONS. 

REQUIREMENTS. 

1 . The same as for raw milk with the exception that the minimum 
dairy score shall be 40, and no milk from a dairy that scores below 
40 shall be pasteurized for sale, except for industrial purposes. 

2. Milk from cows that have been rejected by the tuberculin test, 
but which show no plrysical signs of tuberculosis, as well as those 
which have not been tested, may be sold provided that it is produced 
and handled in accordance with all the other requirements herein 
set forth for pasteurized milk. 

3. Ice used for cooling purposes shall be clean. 

RECOMMENDATIONS. 

The same as for raw milk. 

PASTEURIZED CREAM. 

REQUIREMENTS. 

1. It shall be obtained only from milk that could legally be sold 
as milk under the requirements hereinbefore set forth. 

2. Pasteurized cream, or cream separated from pasteurized milk, 
shall be labeled in the manner herein provided for the labeling of 
pasteurized milk. 

STANDARDS FOR PASTEURIZED MILK. 

REQUIREMENTS. 

1. It shall not contain more than 1,000,000 bacteria per cubic 
centimeter before pasteurization, nor over 50,000 when delivered to 
the consumer, and no colon bacilh in 1 cubic centimeter as deter- 
mined by cultural methods. 

2. The standards for the percentage of milk fat and of total solids 
shall be the same as for raw milk. 

RECOMMENDATIONS. 

1. The limits for the bacterial count before pasteurization and after pasteurization 
should both be lowered if possible. 

STANDARDS FOR PASTEURIZED CREAM. 

REQUIREMENTS. 

1. No cream shall be sold that is obtained from pasteurized milk 
that could not be legally sold under the provisions herein set forth, nor 
shall any cream that is pasteurized after separation contain an exces- 
sive number of bacteria. 

2. The bacterial count of pasteurized cream shall not exceed 
100,000 bacteria per cubic centimeter when delivered to the consumer. 

3. The percentage of milk fat shall be the same as for raw cream. 

Penalty. 

Every milk ordinance should contain a penalty clause. 



22 
APPENDIX. 

REPORT OF THE COMMITTEE UPON THE MICROSCOPIC EXAMINA- 
TION OF MILK AND UPON THE DETERMINATION OF THE DIRT IN 
MILK. 

Inasmuch as the subjects referred to this committee are in some 
respects new to some members of the commission, the report of this 
committee is ■•presented in two parts. In the first part are given the 
important facts concerning the method and the utility of a micro- 
scopic examination of milk, and in the second part are presented a 
few resolutions for consideration by the committee. The data upon 
which this report is based is partly derived from special work by 
members of the committee and partly from correspondence and pub- 
lished papers. Letters have been addressed to all laboratories where 
these methods have been in use, so far as the addresses could be 
obtained, and from the replies received the following conclusion has 
been reached : 

1. The microscopic examination of raw milk has been somewhat 
widely adopted, but apparently only in a few places has it been 
extensively used. In at least two laboratories where it has been 
tried, it has been given up as unreliable; but in general those who 
have used the method most are most enthusiastic as to its value. 

2. There are two different methods of making a microscopic 
examination of milk: 

(a) The use of centrifugal machine by the Stewart-Slack method. 
This method involves the centrifugalization of 1 or 2 cubic centi- 
meters of milk and smearing of the sediment upon a slide, subse- 
quently staining the same, and is so well known that it is unnecessary 
to describe it in detail here. It is the method that has been most 
commonly used. The results of this method vary considerably with 
details of individual manipulation, with the speed of the centrifugal 
machine, with the time allowed for centrifugalization, and with other 
individual factors. As a result, findings of one laboratory can not 
be commonly compared accurately with those of another, but they 
are fairly uniform when compared with each other. 

(b) The direct examination of milk by the Prescott-Breed method. 
The details of this method are found in the Cent. f. Bact. 11, XXX, 
p. 337, 1911, but since it is somewhat new a brief description of it 
will be here given. A capillary tube is prepared, arranged to receive 
a rubber bulb at one end and marked carefully to deliver one one- 
hundredth of a cubic centimeter. After a most thorough mixing of 
the milk, one one-hundredth of a cubic centimeter is removed with 
the sterilized pipette and spread uniformly over a square centimeter 
on an ordinary microscopic slide. It is allowed to dry and is fixed 
with methyl alcohol, after which the fat is dissolved from it by the 
use of xylol. The smear is then stained either with methyline blue 
or preferably with one of the blood stains, the Jenner stain or Wright 
stain being useful for this purpose. If the staining is so deep as to 
make the specimen too opaque for proper study, it is slightly decolor- 
ized with alcohol which removes the stain from the general sediment 
more readily than it does from the bacteria or the tissue cells. The 
stained smear is studied under a twelve-inch immersion. The draw 
tube of the immersion is adjusted so that the field of the miscroscope 
covers exactly 15 millimeters and under these circumstances the 
number of bacteria present in the one one-hundredth of a cubic 



O'l 



centimeter is exactly 5,000 times the number found in a microscopic 
field. The counting of a large number of fields (100 fields) and averag- 
ing the results multiplied by this number will therefore give approxi- 
mately the number of cells or bacteria contained in a one one-hun- 
dredth cubic centimeter of milk. 

This method has the advantage of eliminating all of the errors that 
are associated with the irregularity in the action of the centrifugal 
machine and many of the other individual errors connected with the 
Stewart-Slack method. On the other hand, it has the disadvantage 
of examining only a small quantity of milk, one one-hundredth of a 
cubic centimeter being hardly a fair sample. This disadvantage, 
however, may be met by making a very thorough mixture of the 
milk before sampling and by making the examination in duplicate. 
A second disadvantage is the large multiplier that has to be used to re- 
duce the results to 1 cubic centimeter. This, of course, very greatly 
increases any error that may appear in the observation and intro- 
duces an error the extent of which can not yet be stated accurately. 
It may in a measure be met by making the examination in duplicate 
and by averaging a large number of plate counts. 

3. The chief advantages derived from the microscopic examination 
of milk are due to the quickness of the method: 

(a) It makes possible the rapid discarding of poor samples of milk, 
since reports upon it are possible within a very short time. 

(b) The quickness with which an examination can be made makes 
it possible for a single laboratory to examine many more samples of 
milk than by the older plate method, one person being able to examine 
and report upon 50 to 100 samples in a half day, and to make the re- 
ports upon the same day that the milk is collected. 

4. The microscopic study of milk gives information upon the follow- 
ing points: 

(a) The abundance of cells which are present in the milk. 

(b) The clumping of these cells, which is frequently noticeable in 
the centrifugal slime but which is rarely if ever seen in milk that is 
examined by the direct method above mentioned. 

(c) The bacterial count. 

(d) The presence of chain-forming streptococci (in this report when 
the term streptococci is used, reference is made to chain-forming 
organisms with at least six elements in a chain). 

(e) General information concerning the nature of the dirt and the 
source of the bacteria in the milk. With a little experience one can 
distinguish certain types of bacteria which comes from farm dirt from 
those that come from unclean vessels. 

5. The estimation of the number of bacteria in milk by microscopic 
study has the following advantages and disadvantages: 

(a) It is of no value when the number of bacteria in the milk is low. 

(b) The microscopic examination gives numbers of bacteria vastly 
higher than those given by the plate method. (In a series of 20 com- 
parative tests by one member of the committee there was found an 
average of 5,000 bacteria by the plate method. 700,000 bacteria by 
the Stewart-Slack method, and 5,000,000 bacteria by the Prescott- 
Breed method of microscopic examination.) 

(c) In determining the total number of bacteria in milk the 
microscopic examination is far more accurate than the plate method, 
since it gives practically all of the bacteria present, while the plate 
method gives only those that grow in special media under special 



24 

conditions. The microscope, however, fails to distinguish between 
living and dead bacteria. 

(d) The Stewart-Slack method of examining milk is of great practi- 
cal use in those cities which have a bacterial standard of 500,000, 
since it quickly detects milk which contains bacteria more than this 
limit without the necessity of making plate count. For samples 
that contain about 500,000 or less it is necessary to make a plate count 
in order that the result may be reliable. 

(e) The data at hand are as yet insufficient to determine the factor by 
which the milk could be condemned by the Prescott-Breed method. 
Data at present at hand would seem to indicate that nearly all samples 
of milk would approach or surpass this limit of 500,000 when the 
bacteria are determined by the direct method of examination of 
Prescott-Breed. 

(/) No constant ratio can be found between the number of bacteria 
disclosed by the miscroscope and the number found by the plate 
count. There is a general parallel but with many irregularities. 

6. No method has yet been accepted for accurately distinguishing 
between the pus cells and other cells that may be in the milk that do 
not have an origin in inflammatory conditions. Some regard all 
noticeably clumped cells as indicating pus, stating that upon proper 
incubation, all such dumpings may be found to be accompanied by 
chain-forming streptococci. Others regard all polymorphonuclear 
neutrophilic cells as pus. Most, however, at the present time fail to 
recognize any method of clearly distinguishing pus from tissue cells. 

7. A general consensus of opinion has been reached that a high 
cell count should not alone condemn milk, although it is a matter 
for suspicion. The cell count varies with the same cow upon differ- 
ent days and it may be increased by simply manipulating the 
udders. Some believe that clumped cells always indicate an inflam- 
matory condition. 

8. A high cell count accompanied by streptococci apparently 
always indicates udder troubles. In many cases these have been 
followed up to the dairy, and where this has been done it is almost 
always possible to find the source in some cow suffering from some 
trouble in its udders. 

9. More data is needed before it can be definitely stated whether 
ill health in children can be traced to milk that would be condemned 
by the microscope, although this has apparently been done in some 
cases. 

10. At the present time, it is impossible to agree upon any standard 
for condemning milk by cell count beyond the general rule that a 
high cell count accompanied by streptococci indicates an inflamma- 
tory condition or otherwise diseased udders. 

11. Where the source of the milk is known, microscopic method of 
study is of great value in picking out animals with diseased udders. 
It is of a special help in directing attention to a herd that needs inspec- 
tion, and has been extensively and satisfactorily used in this way. In 
market milk, it is of great value where the source of the milk is known 
and can be reached, and its chief value is in finding the location of 
troubles rather than in condemning milk. 

12. Concerning the value of the microscopic examination of milk, 
there are wide differences of opinion among those who have been 
using it. A few regard it as of little value and have discarded it 
entirely. Some have thought it of some value, but much less than 



25 

the bacteriological plate count. Others regard it of more value than 
the plate count; and some have looked upon it as of so much value 
as to lead them to substitute it for the older method of bacteriological 
examination by plates, this latter method of examining having been 
quite abandoned. The claim is made in these cases that it gives 
better and quicker results and has been found of practical value in 
controlling the milk supply by pointing out the sources of trouble. 
All who have used this method recognize that it gives valuable data. 

13. Concerning the dirt test, the committee would make the fol- 
lowing statement: Of the several methods of determining the pres- 
ence of dirt in milk the committee believe that the most valuable is 
that of filtering it through a. cotton disk. This committee would 
suggest that a standard disk of an inch in diameter be selected for 
the filtering of a quart of milk, and proportionate-sized disk for smaller 
amounts of milk. The Lorenze apparatus is a convenient filter for 
filtering milk through a cotton disk; but various other types than that 
distinctly known by this name are equally satisfactory. A Gooch cru- 
cible may be used conveniently or any other device in which the cotton 
disk is supported upon a gauze and in such position that milk can be 
readily filtered through it. To be most efficient, the cotton disk 
should be subsequently dried and sent to the individual dairyman. 

In order to have the best results, the most desirable plan is to do 
the filtering in the dairy immediately after milking. For this purpose 
batteries of filters are needed, and these must be warmed in cold 
weather in order that milk should pass through them readily. If 
these are used in the dairy, the results thus demonstrated to the dairy- 
man are very convincing. The test is quick and simple and is proving 
very useful in locating unclean methods. It is much less cumbersome 
than the somewhat more expensive method of measuring the amount 
of dirt, and although it does not give a quantitative, but only com- 
parative result, it is as useful for the purpose of detecting and rem- 
edying unclean conditions as the more slow and more expensive 
quantitative methods. 

From these data the committee would present the following rec- 
ommendations : 

RECOMMENDATIONS. 

1. The direct microscopical examination of raw milk gives very 
valuable information, since it presents in a few moments a graphic 
picture of the bacterial content as well as the number of cells and 
offers a prompt method of excluding some samples of milk which are 
manifestly unfit for use, doing this promptly. To give the most val- 
uable results, the committee would recommend the use of some good 
blood stain like the Jenner or the Wright stain. 

2. Because of the irregularities in methods and results, no standard 
can yet be given for grading milk by the microscopic examination. 
Special attention is recommended to the presence of polymorpho- 
nuclear neutrophilic cells. A high cell count alone is not sufficient to 
condemn milk, but if accompanied by chain-forming streptococci it is 
an indication of udder troubles. The presence of streptococci alone 
is also sufficient to suggest the same conclusion. The microscopic 
examination is therefore of great use in picking out animals with dis- 
eased udders for the purpose of removing them from the dairy herd 
after a proper examination of individual cows. 



26 

3. The data as yet accumulated are insufficient to determine 
whether the examination of milk by the centrifugal method of the 
Stewart-«Slack type or the direct examination by the Prescott-Breed 
method gives the most reliable results. 

4. The total numbers of bacteria found by the microscopic exam- 
ination are so out of proportion to those given by those of the plate 
method that no ratio can be at present drawn between them. 

5. The data which have as yet been collected are insufficient to 
determine whether the microscopic examination of pasteurized milk 
is of any value. 

6. Trie determination of dirt by filtering a quart of milk through a 
cotton disk of an inch in diameter is advised as of the greatest value 
in detecting uncleanly conditions and in conveying a most graphic 
lesson of the need of cleanliness to the dairyman. Preferably this 
should be done in the dairy where feasible. 

METHODS OF REPORTING BACTERIAL COUNTS. 

CLASSIFICATION OF DEALERS' MILKS. 

The commission recommends the use of North's modification of 
Levy's method of giving each bacterial count a rating value. This 
modification consists in the use of such values as can be obtained from 
a parabolic curve having as ordinates the ratings and as abscissas the 
bacteria counts. The final statement of a series of bacterial counts 
is given as a single figure which expresses the sanitary character of 
the milk in terms of bacteria per cubic centimeter. This figure, it is 
recommended, shall be known as the "bacterial content." 

To warrant a statement of the class or grade in which a given milk 
belongs, at least four consecutive counts should be made of separate 
samples of milk taken within a period of not more than four weeks. 

All laboratory workers are familiar with the fact that the differ- 
ences in sanitary importance of high and low bacterial counts are 
not proportional to the numerical differences. It is recognized that 
bacteria multiply in geometric progression. A single germ may 
divide, under favorable conditions, about once every half hour, so 
that from 1 it will have increased to 281,474,976,710,656 within 24 
hours. This means that under favorable conditions, if there were 
no interruptions and no deaths, 1 germ in a 40-quart can of milk 
might multiply in 24 hours, so that 1 cubic centimeter of milk would 
contain over 7,438,000,000. The ability of some bacteria to multiply 
with extreme rapidity is the reason why high counts should not be 
given the same value which is given to low counts. 

The method proposed for stating the results of bacterial counts 
aims to recognize all high counts but at the same time to prevent 
them from misrepresenting the real character of the milk. The 
method may at first seem complicated because of its use of higher 
mathematics, but as a matter of fact is extremely simple. 

THE PARABOLIC CURVE. 

Without going into a discussion of the properties of the different 
mathematical curves, it can be stated that a parabola is a regular 
curve, which increases its distance far more rapidly in a horizontal 
direction than in a vertical direction, or vice versa, and, conse- 
quently, lends itself to the conditions of the problem which faces 



27 



the bacteriologist who has, on the one hand, bacteria counts which 
increase enormously in the higher figures, while on the other he has 
values which he desires to attach to the same, which do not differ 
so enormously. The values for bacteria counts obtained from the 
parabola are as follows: 
Where 

y 2 =X 1/100. 

x = bacteria count. 

y = rating corresponding. 



Bacteria 


Normal 


Bacteria 


Normal 


Bacteria 


Normal 


counts. 


rating. 


counts. 


rating. 


counts. 


rating. 


100 


1.00 


9,000 


9.5 


300,000 


54.8 


200 


1.41 


10,000 


10.0 


400,000 


63.2 


300 


1.73 


15,000 


12.3 


500,000 


70.8 


400 


2.00 


20,000 


14.1 


600,000 


77.5 


500 


2.24 


25,000 


15.8 


700,000 


83.7 


600 


2.45 


30,000 


17.3 


800, 000 


89.5 


700 


2.65 


35,000 


18.7 


900,000 


95.0 


800 


2.83 


40,000 


20.0 


1,000,000 


100.0 


900 


3.00 


45,000 


21.2 


2,000,000 


141.0 


1,000 


3.16 


50,000 


22.4 


3,000,000 


173.0 


2,000 


4.47 


60,000 


24.5 


4,000,000 


200.0 


3,000 


5.48 


70,000 


26.4 


5,000,000 


224.0 


4,000 


6.32 


80,000 


28.3 


6,000,000 


245.0 


5,000 


7.08 


90,000 


30.0 


7,000,000 


265.0 


6,000 


7.75 


100, 000 


31.6 


8,000,000 


283.0 


7,000 


8.37 


200, 000 


44.7 


9,000,000 


300.0 


8,000 


8.95 


250, 000 


50.0 


10,000,000 


316.0 



From the diagram of the parabolic curve shown on page 699 the 
values in the table given were taken. For any bacterial count a cor- 
responding value can be found by observing the point on the curve 
intersected by the line leading upward from the bacterial count 
and following the line of rating value which leads to the right or left 
at this point. Thus the line leading upward from 10,000 bacteria 
strikes the curve at a point through which passes the line leading to 
the left having rating value 10, and bacterial line 40,000 meets curve 
at point intersected by line of rating value 20; bacterial line 1,000,000 
meets rating line 100. 

In the figure the curve from 40,000 to 100,000 bacteria is much 
condensed to save space, and from 100,000 to 1,000,000, and again to 
4,000,000, is still further condensed; these shortenings account for 
disjointed appearance. 

This table is used as follows : Assume that a health board laboratory 
makes four consecutive examinations of the milk of a single dealer, 
and that these are as follows: 25,000, 70,000, 250,000, and 5.000,000. 
It desires to determine in what class this milk belongs. To express 
the character of the milk in a single figure set opposite each bacteria 
count the normal rating value found in the above table. This would 
be as follows : 



Bacteria count. 


• Normal ratings. 


25,000 

70,000 

250,000 

5,000,000 


15.8 

26.4 

50.0 

224.0 


4) 316.2 

79.0=600,000+ 



28 

After the normal ratings are obtained for each figure, they are 
added together and averaged, as shown above, giving the average 
rating 79. Again referring to the table it will be observed that the 
nearest figure in the normal rating column is 77.5, opposite which is 
the bacteria count of 600,000. Consequently, the final character 
of the milk will be expressed by the figure 600,000 bacteria per cubic 
centimeter. Pursuing this system with all milks makes it possible 
to express their character in a single figure in terms of bacteria, which 
it is suggested should be called "the bacterial content." 

THE RATING OF A CITY'S ENTIRE MILK SUPPLY. 

In the annual report of a city's department of health it is often 
desirable to compare the results of one year's work with another, or 
to compare one city's standing with that of another. For these pur- 
poses the commission recommends the use of the Levy method of 
stating the results of bacterial counts. In this method the bacterial 
counts are first divided into groups, as recommended by the American 
Public Health Association. To each of these groups certain per- 
centage values are given. The final expression is made as a single 
figure in terms of percentage. 

The groups and the percentage values recommended for each are as 
follows : 



Bacteria. 



Under 10,000.... 
10,001 to 50,000.. 
50,001 to 100,000. 
100,001 to 250,000 



Rating 
figure. 



Per cent. 
100 
90 
75 
50 



Bacteria. 



250,001 to 500,000. . 
500,001 to 1,000,000 
Over 1,000,000 



Rating 
figure. 



Per cent. 
20 
10 




In using the above table all of the bacterial counts are first divided 
into groups, stating the number in each group. Each number is then 
muliplied by the percentage value of its group, as illustrated in the 
following: table: 



Bacteria. 



Number 

of 
samples. 



Rating 
figure. 



Product. 



Under 10,000 

10,001 to 50,000..., 
50,001 to 100,000... 
100,001 to 200,000.. 
250,001 to 500,000.. 
500,001 to 1,000,000 
Over 1,000,000 

Total 



Per cent. 
100 
90 
75 
50 
20 
10 




265 



2,500 
6,570 
2,775 
2,100 
1,060 
230 




15,235 



15,235 
265 



=A verage=57 per cent. 



29 

The final statement, which is the average of all percentages, is 
called by Levy the "bacterial index." 

In reporting results of laboratory work under city conditions it is 
desirable that a more detailed statement be given than the single 



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figures of "bacterial content" and "bacterial index," and it is there- 
fore recommended that all tests made or at least all in each group be 
reported when possible as approved by the laboratory section of the 
American Public Health Association. 



30 



TIML AMD TE.MPLRATURE. FOR 
n(o" MILK PASTEURIZATION. 




10' 10' 30' 4.0' 

Tl ME. IN MINUTL5 



REPRINTS FROM PUBLIC HEALTH REPORTS. 

[Those marked (*) are exhausted and no longer available for distribution. Those marked (f) may be 
purchased from the Supjrintendent of Documents at 5 cents a copy. Copies of the Public Health 
Reports containing these articles will be found in most public libraries, as will also the reprints 
themselves.] 

fl. Precis upon the Diagnosis and Prevention of Smallpox. Reprint from P. H. R. 

No. 1, Vol. XIV, January 6, 1899. 14 pages. Paper. 
2. Plan of Organization for Suppression of Smallpox in Communities not provided 
with an Organized Board of Health. By G. P. Wertenbaker. Reprint 
from P. H. R. No. 42, Vol. XIV, October 20, 1899. 23 pages. Paper. 

*3. Mortality Statistics of 1,433 Cities and Towns of the United States for the Year 

Ended December 31, 1898. Reprint from P. H. R. November 10. 1899. 24 

pages. Paper. Out of print. 

4. The Prophylaxis of Plague by Preventive Inoculations. By Dr. A. Calmette, 

Director of the Pasteur Institute of Lille. Reprint from P. H. R. No. 34, 

Vol. XIV, August 24, 1900. 4 pages. Paper. 

*5. The International System of Nomenclature of Diseases and Causes of Death 
(Bertillon Classification, as adopted by the Eighth International Congress 
of Hygiene and Demography, Paris, August 18-21, 1900. Translated by 
H. D. Geddings). Reprint from P. H. R. No. 49, Vol. XV, December 7, 
1900. 47 pages. Paper. Out of print. 
6. Yellow Fever Institute. Description of Organization. By Surgeon General 
Wyman. Reprint from P. H. R. No. 39, Vol. XVI, September 27, 1901. 
7 pages. Paper. 

*7. Mortality Statistics of 1,190 Cities and Towns of the United States for the Year 
ended December 31, 1900. Reprint from P. H. R. No. 40, Vol. XVI, October 
4, 1901. 23 pages. Paper. Out of print. 
8. Plan for International Agreement of the American Republics for the Sanitation 
of Certain Seacoast Cities. By Surgeon General Walter Wyman. Reprint 
from P. H. R. No. 41, Vol. XVI, October 11, 1901. 13 pages. Paper. 

f9. The Prevention of the Spread of Scarlet Fever. By H. D. Geddings. Reprint 

from P. H. R. No. 3^ Vol. XVII, January 17, 1902. 8 pages. Paper. 
flO. Public Health and Marine-Hospital Service of the United States. An act to 
increase the efficiency and change the name of the United States Marine- 
Hospital Service. Reprint from P. H. R. No. 27, Vol. XVII, July 4, 1902. 
4 pages. Paper. 
*11. Plague Conference. Containing a copy of the address of the chairman and reso- 
lutions passed by a conference called in accordance with request from a 
number of State boards of health, and under authority of section 7, act of 
Congress approved July 1, 1902, to consider the plague situation. Reprint 
from P. H. R. No. 4, Vol. XVIII, January 23, 1903. 9 pages. And Febru- 
ary 6, 1903. 41 pages. Paper. Out of print. 

12. Prophylaxis against Yellow Fevei. (Extract from a paper read by Dr. J nan 
Guiteras before the First International Sanitary Conference of American 
Republics, held in Washington, D. C, December 2-5, 1902.) . Reprint from 
P. H. R. No. 31, Vol. XVIII, July 31, 1903. 6 pages. Paper. 
*13. Mortality Statistics of 1,563 Cities and Towns of the United States for the Year 
ended December 31, 1902. Reprint from P. H. R. No. 32, Vol. XVII 1, 
August 7, 1903. 27 pages. Paper. Out of print. 

(i) 



II 

*14. Precis on the Fly aud Mosquito as Carriers of Disease. By H. D. Geddings. 

Reprint from P. H. R. No. 35, Vol. XVIII, August 28, 1903. 10 pages. 

Paper. Out of print. 
+15. Precis on the Management of Outbreaks of Smallpox, Diphtheria, and Scarlet 

Fever. By H. D. Geddings. Reprint from P. H. R. No. 38, Vol. XVIII, 

September 18, 1903. 18 pages. Paper. 
fl6. Concerning the Geographic Distribution of the Yellow Fever Mosquito. By 

L. O. Howard. Reprint from P. H. R. No. 46, Vol. XVIII, November 13, 

1903. Out of print. The above revised to September 10, 1905. 14 pages. 

Paper. 
*17. Second General International Sanitary Convention of the American Republics, 

concluded at Washington, D. O, October 14, 1905. Reprints from P. H. R. 

No. 5, Vol. XXII, February 1, 1907. 9 pages. Paper. Out of print. 
*18. Brief History of Federal and State Action against Tuberculosis in the United 

States. Reprint from P. H. R. No. 8, Vol. XXII, February 22, 1907. 18 

pages. Paper. Out of print. 
tl9. The Fourth Disease (Filatow-Dukes Disease). By J. W. Schereschewsky. 

Reprint from P. H. R. No. 19, Vol. XXII, May 10, 1907. 7 pages. Paper. 
*20. The Climate of New Mexico. By Paul M. Carrington. Reprint from P. H. R. 

No. 28, Vol. XXII, July 12, 1907. 15 pages. Paper. Out of print. 

21. Dengue Fever, as Observed in Brownsville, Tex., August, 1907. By Joseph 

Goldberger and George W. McCoy. Reprint from P. H. R. No. 49, Vol. 

XXII, December 6, 1907. 7 pages. 3 charts. Paper. 

22. Plague Investigations in India. Reprint from P. H. R. No. 50, Vol. XXII, 

December 13, 1907. 21 pages. Paper. 

23. The Prophylactic Value of Vaccination. By Henry S. Mathewson. Reprint 

from P. H. R. No. 5, Vol. XXIII, January 31, 1908. 9 pages. Paper. 
(Second edition.) 

*24. How to Trap Rats. By W. C. Rucker. Reprint from P. H. R. No. 9, Vol. 

XXIII, February 28, 1908. 4 pages. Paper. Out of print. 

*25. Request for Fleas for Identification and for Information Relative to Local Species 

of Fleas, Rats, and Mice. Reprint from P. H. R. No. 10, Vol. XXIII, 

March 6, 1908. 4 pages. Paper. 
26. Measures to Prevent the Introduction and Spread of Plague. Reprint from 

P. H. R. No. 22, Vol. XXII, May 29, 1908. 9 pages. Paper. 
+27. The Danger and Prevention of Tetanus from Fourth of July Wounds. By John 

F. Anderson. Reprint from P. H. R. No. 25, Vol. XXIII, June 19, 1908. 

4 pages. Paper. 

28. Prevention and Destruction of Mosquitos. By Joseph Goldberger. Reprint 

from P. H. R. No. 29, Vol. XXIII, July 17, 1908. 11 pages. Paper. (3d 

edition.) 
+29. Notes on Rat Leprosy and the Fate of Human and Rat Lepra Bacilli in Flies. 

By Wm. B. Wherry. Reprint from P. H. R. No. 42, Vol. XXIII, October 

16, 1908. 8 pages. Paper. 
+30. California Ground Squirrels. By C. Hart Merriam. Reprint from P. H. R. 

No. 52, Vol. XXIII, December 25, 1908. 8 pages. Paper. 
+31. Experimental Investigation of Biting of Man by Fleas from Rats and Squirrels. 

By George W. McCoy and Maurice B. Mitzmain. Reprint from P. H. R. 

No. 8, Vol. XXIV, February 19, 1909. 9 pages. Paper. 
+32. Campaign Against Ground Squirrels in Contra Costa County, California. By 

Rupert Blue. Reprint from P. H. R. No. 21, Vol. XXIV, May 21, 1909. 

5 pages. Paper. 

*33. Colored Antituberculosis League. Proposed Plan of Organization. By C. P. 
Wertenbaker. Reprint from P. H. R., No. 22, Vol. XXIV, May 28, 1909. 
9 pages. Paper. Out of print. 



Ill 

f34. The Prevalence of Pellagra in the United States. A Statistical and Geographical 

Note with Bibliography. By C. H. Lavinder, C. F. Williams, and J. W. 

Babcock. Reprint from P. H. R., No. 25, Vol. XXIV, June 18, 1909. 6 

pages. Paper. 
f35. Epidemic of an Urticarioid Dermatitis Due to a Small Mite (Pediculoides ventri- 

cosus) in the Straw of Mattresses. By Joseph Goldberger and Jay F. 

Schamberg. Reprint from P. H. R., No. 28, Vol. XXIV, July 9, 1909. 

6 pages. Paper. 
f36. Hookworm Disease in its Relation to the Negro. By Ch. Wardell Stiles. Reprint 

from P. H. R., No. 31, Vol. XXIV, July 30, 1909. 10 pages. Paper. 

37. The Treatment of Hookworm Disease. By Ch. Wardell Stiles. Reprint from 

P. H.R., No. 34, Vol. XXIV, August 20, 1909. 5 pages. Paper. 

38. Plague Among Ground Squirrels in Contra Costa County, California. By W. C. 

Rucker. Reprint from P. H. R., No. 35, Vol. XXIV, August 27, 1909. 18 
pages. Paper. 

39. A Working Plan for Colored Antituberculosis Leagues. By C. P. Wertenbaker. 

Reprint from P. H. R., No. 36, Vol. XXIV, September 3, 1909. 12 pages. 

Paper. 
f40. Notes on the Prognosis and Treatment of Pellagra. By C. H. Lavinder. Reprint 

from P. H. R., No. 37, Vol. XXIV, September 10, 1909. 10 pages. Paper. 
41. The Second International Conference on Leprosy, held in Bergen, Norway, 

August 16 to 19, 1909. By Donald H. Currie. Reprint from P. H. R., 

No. 38, Vol. XXIV, September 17, 1909. 10 pages. Paper. 
f42. Soil Pollution and its Relation to Hookworm Disease and Typhoid Fever. By 

Ch. Wardell Stiles. Reprint from P. H. R., Vol. XXIV, No. 40, October 1, 

1909. 10 pages. 3 illustrations. Paper. 

f43. The Prophylaxis of Pellagra. By C. H. Lavinder. Reprint from P. H. R., Vol. 
XXIV, No. 44, October 29, 1909. 13 pages. Paper. 

44. Summary of Transactions of the Public Health and Marine-Hospital Service, 

Fiscal Year 1909, and to November 1, 1909. Reprint from P. H. R., Vol. 

XXIV, No. 50, December 10, 1909. 16 pages. Paper. 

45. The Evidence of Plague Infection Among Ground Squirrels. By George W. 

McCoy. Reprint from P. H. R,, Vol. XXV, No. 2, January 14, 1910. 8 
pages. Paper. 

46. What the Local Health Officer Can Do in the Prevention of Typhoid Fever. 

By L. L. Lumsden. Reprint from P. H. R., Vol. XXV, No. 5, Felruary 4, 

1910. 14 pages. Paper. (Second edition.) 

f47. The Straw Itch (Dermatitis Schambergi) : A Disease New to American Physicians. 
By Joseph Goldterger. Reprint from P. H. R,, Vol. XXV, No. 23, June 10, 
1910. 8 pages. 2 illustrations. Paper. 

48. What the Mayor and City Council Can Do in the Prevention of Typhoid Fever. 

By L. L. Lumsden. Reprint from P. H. R,, Vol. XXV, No. 24, June 17, 
1910. 14 pages. Paper. (Second edition.) 

49. The Present Organization and Work for the Protection of Health in the United 

States. By Walter Wyman. Reprint from P. H. R., Vol XXV, No. 38, 

September 23, 1910. 13 pages. Paper. (Second edition.) 
*50. The History, Development, and Statistics of Milk Charities in the United States. 

By J. W. Kerr. Reprint from P. H. R., Vol. XXV, No. 39, September 30, 

1910. 19 pages. Paper. Out of print. 
f51. Pulmonary Hemorrhage in the Tuberculous at High Altitude (6,200 feet) ; Report 

of 56 Deaths; Frequency of Associated Heart Disease. By F. C. Smith. 

Reprint from P. H. R., Vol. XXV, No. 40, October 7, 1910. 9 pages. Paper. 
52. Bacteriological Procedure in Suspected Cholera, with Report of a Positive Case. 

By John F. Anderson and A. M. Stimson. Reprint from P. H. R., Vol. 

XXV, No. 42, October 21, 1910. 5 pages. Paper. 



IV 

53. Cholera: Its Nature, Detection, and Prevention. By A. J. McLaughlin. Reprint 
from P. H. R., Vol. XXV, No. 44, November 2, 1910. 20 pages. Paper. 
(Third edition.) 

t54.jPreliminary Note on a Simple and Inexpensive Apparatus for Use in Safe Dis- 
posal of Night Soil. By L. L. Lumsden, Norman Roberts, and Ch. Wardell 
Stiles. Reprint from P. H. R., Vol. XXV, No. 45, November 11, 1910. 7 
pages. 1 il. Paper. 

f.55. The Field Investigation of Epidemic Poliomyelitis (What the Health Officer Can 
Do Toward Solving a National Problem). By W. H. Frost. Reprint from 
P. H. R., Vol. XXV, No. 46, November 18, 1910. 19 pages. References 
Paper. 

f56. Report on an Outbreak of Typhoid Fever at Des Moines, Iowa. By L. L 
Lumsden. Reprint from the P. H. R., Vol. XXVI, No. 4, January 27, 1911. 
26 pages. 2 charts. 1 map. Paper. 

f57. Smallpox and Vaccination in the Philippine Islands. By Victor G. Heiser and 
Robert Oleson. Reprint from the P. H. R., Vol. XXVI, No. 10, March 10, 
1911. 6 pages. Paper. 

f58. The Typhoid Bacillus Carrier: A Review. By R. M. Grimm. Reprint from 
the P. H. R., Vol. XXVI, No. 11, March 17, 1911. 17 pages. Paper. 

59. Report on an Original Form of Sulphur Burner for Disinfection. By N. Roberts 

and F. Alex. McDermott. Reprint from the P. H. R., Vol. XXVI, No. 13, 

March 31, 1911. 10 pages. 2 charts. 1 il. Paper. 
f60. A Note on Smallpox and Vaccination in the Philippine Islands. By Victor G. 

Heiser. Smallpox and Vaccination in Cuba. By P. Villoldo. Reprint 

from the P. H. R., Vol. XXVI, No. 15, April 14, 1911. 7 pages. Paper. 
61. Smallpox in the United States.— Prevalence and Geographic Distribution during 

the Calendar Year 1909. By John W. Trask. Reprint from P. H. R., Vol. 

XXVI, No. 22, June 2, 1911. 9 pages. 1 table. 2 maps. Paper. 
f62. Experimental Measles in the Monkey: A Supplemental Note. By John F. 

Anderson and Joseph Goldberger. Reprint from the P. H. R., Vol. XXVI, 

No. 24, June 16, 1911. 11 pages. 2 charts. Paper. 
03. Smallpox in the United States — Prevalence and Geographic Distribution during 

the Calendar Year 1910. By John W. Trask. Reprint from the P. H. R., 

Vol. XXVT, No. 25, June 23, 1911. 13 pages. 2 tables. 2 maps. Paper. 

64. Data Regarding Operations of Infants' Milk Depots in the United States in 1910. 

By J. W. Kerr. Reprint from the P. H. R., Vol. XXVI, No. 33, August 18 ; 

1911. 20 pages. 8 tables. Paper. 

65. The Salient Epidemiological Features of Pellagra. By C. H. Lavinder. Reprint 

from the P. H. R., Vol. XXVI, No. 39, September 29, 1911. 11 pages. 
Paper. 

60 . Antityphoid Vaccination. Extracts from the Report of the Commission appointed 

1 y the Academy of Medicine of Paris. Translation by Joseph W. Schere- 
schewsky. Reprint from the P. H. R., Vol. XXVI, No. 40, October 6, 1911. 
25 pages. Paper. (Second edition.) 
07. Origin and Prevalence of Typhoid Fever in Fort Smith, Ark., and Measures 
Necessary for its Control. By W. H. Frost. Reprint from the P. H. Tl., 
Vol. XXV T , No. 43, October 27, 1911. 19 pages. Paper. 

68. The Tarbagan (Arctomys bobac) and Plague. By Paul Preble. Reprint from 

P. H. R., Vol. XXVII, No. 2, January 12, 1912. 10 pages. Bibliography. 
Paper. 

69. Epidemic Cerebrospinal Meningitis. A Review of its Etiology, Transmission, 

and Specific Therapy, with Reference to Public Measures for its Control. 
By W. H. Frost. Reprint from P. H. R., Vol. XXVII, No. 4, January 26, 

1912. 27 pages. Paper. (Second edition.) 



70. Municipal Ordinances, Rules, and Regulations Pertaining to Public Hygiene. 
Adopted from January 1, 1910, to June 30, 1911, by Cities of the United 
States Having a Population of over 25,000 in 1910. Prepared by direction 
of the Surgeon General. Reprint from Public Health Reports of March 24, 

1911, to January 19, 1912, inclusive. Paper. 

f71. The Relation of So-called Brill's Disease to Typhus Fever. An Experimental 
Demonstration of Their Identity. By John F. Anderson and Joseph Gold- 
berger. Reprint from P. H. R., Vol. XXVII, No. 5, February 2, 1912. 
14 pages. 6 charts. Paper. 

72. Vegetables as a Possible Factor in the Dissemination of Typhoid Fever. By 

R. H. Creel. Reprint from P. H. R., Vol. XXVII, No. 6, February 9, 1912. 
9 pages. Paper. (Second edition.) 

73. Typhus Fever in the United States. Differential Diagnosis from Typhoid Fever. 

Reprint from P. H. R., Vol. XXVII, No. 6, February 9, 1912. 5 pages. 
Paper. 

74. The Transmission of Typhus Fever, with Especial Reference to Transmission by 

the Head Louse (Pediculosis capitis). By Joseph Goldberger and J. F. 
Anderson. Reprint from P. H. R., Vol. XXVII, No. 9, March 1, 1912. 
13 pages. 6 charts. Paper. 

75. The Bacteriological Diagnosis of Cholera. A Report Presented to the Perma- 

nent Committee of the International Office of Public Hygiene in the name 
of a Commission Composed of: Messrs. Ruffer, president; Calmette, Gaffky, 
Geddings, Murillo, Praum, and Pottevin, reporter. Translated from the 
French by Surg. H. D. Geddings, American Delegate on the Permanent 
Committee. Reprint from P. H. R., Vol. XXVII, No. 11, March 15, 1912. 
30 pages. Paper. 

76. The Necessity for Safe Water Supplies in the Control of Typhoid Fever. By 

A. J. McLaughlin. Reprint from P. H. R., Vol. XXVII, No. 12, March 22, 

1912. 13 pages. 5 tables. Paper. (Second edition.) 

77. Sewage- Polluted Water Supplies in Relation to Infant Mortality. By Allan J. 

McLaughlin. Reprint from P. H. R., Vol. XXVII, No. 17, April 26, 1912. 
36 pages. 24 charts. Paper. 

78. Report of the Commission on Milk Standards Appointed by the New York Milk 

Committee. Reprint from P. H. R., Vol. XXVII, No. 19, May 10, 1912. 
30 pages. 2 charts. Paper. (Second edition.) 

79. Investigation of and Tick Eradication in Rocky Mountain Spotted Fever. By 

Thomas B. McClintic. Reprint from P. H. R., Vol. XXVII, No. 20, May 17, 
1912. 31 pages. Bibliography. Paper. 

80. Examination of Excreta for Typhoid Bacilli. By L. L. Lumsden and A. M. 

Stimson. Report of an Outbreak of Typhoid Fever at Lincoln, Nebraska, in 
1911. By L. L. Lumsden. Reprint from P. H. R., Vol. XXVII, No. 21, 
May 24, 1912. Paper. 

81. Sanitary Advice for Summer Tourists. Sanitary Advice for the Keepers of Sum- 

mer Resorts. By W. C. Rucker. Reprint from P. H. R., Vol. XXVII, 
No. 21, May 24, 1912. Paper. 

82. Studies on the Virus of Typhus. By John F. Anderson and Joseph Goldberger. 

Reprint from P. H. R,, Vol. XXVII, No. 22, May 31, 1912. Paper. 

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